diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e782bd..3e2b257 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 Represents the **NuGet** versions.
 
+## v2.4.0
+- *Enhancement:* Added `MigrationAssemblyArgs` to allow for the specification of zero or more `Data` folder names.
+- *Fixed:* Updated `CoreEx` to version `3.9.0`.
+
+
 ## v2.3.15
 - *Fixed:* Updated `CoreEx` to version `3.8.0`.
 - *Fixed:* Updated `OnRamp` to version `2.0.0` which necessitated internal change from `Newtonsoft.Json` (now deprecated) to `System.Text.Json`; additionally, the `DataParser` was refactored accordingly.
diff --git a/Common.targets b/Common.targets
index aad69b9..948c28e 100644
--- a/Common.targets
+++ b/Common.targets
@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>2.3.15</Version>
+    <Version>2.4.0</Version>
     <LangVersion>preview</LangVersion>
     <Authors>Avanade</Authors>
     <Company>Avanade</Company>
diff --git a/src/DbEx.MySql/DbEx.MySql.csproj b/src/DbEx.MySql/DbEx.MySql.csproj
index dfe9a9d..ff43fcf 100644
--- a/src/DbEx.MySql/DbEx.MySql.csproj
+++ b/src/DbEx.MySql/DbEx.MySql.csproj
@@ -39,7 +39,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="CoreEx.Database.MySql" Version="3.8.0" />
+    <PackageReference Include="CoreEx.Database.MySql" Version="3.9.0" />
     <PackageReference Include="dbup-mysql" Version="5.0.37" />
   </ItemGroup>
 
diff --git a/src/DbEx.MySql/Migration/MySqlMigration.cs b/src/DbEx.MySql/Migration/MySqlMigration.cs
index 2a34f9e..81662de 100644
--- a/src/DbEx.MySql/Migration/MySqlMigration.cs
+++ b/src/DbEx.MySql/Migration/MySqlMigration.cs
@@ -25,7 +25,7 @@ public class MySqlMigration : DatabaseMigrationBase
         private readonly string _databaseName;
         private readonly IDatabase _database;
         private readonly IDatabase _masterDatabase;
-        private readonly List<string> _resetBypass = new();
+        private readonly List<string> _resetBypass = [];
 
         /// <summary>
         /// Initializes an instance of the <see cref="MySqlMigration"/> class.
@@ -48,7 +48,7 @@ public MySqlMigration(MigrationArgsBase args) : base(args)
 
             // Defaults the schema object types unless already specified.
             if (SchemaObjectTypes.Length == 0)
-                SchemaObjectTypes = new string[] { "FUNCTION", "VIEW", "PROCEDURE" };
+                SchemaObjectTypes = ["FUNCTION", "VIEW", "PROCEDURE"];
 
             // Add/set standard parameters.
             Args.Parameter(MigrationArgsBase.DatabaseNameParamName, _databaseName, true);
diff --git a/src/DbEx.SqlServer/DbEx.SqlServer.csproj b/src/DbEx.SqlServer/DbEx.SqlServer.csproj
index 7084a7e..8e05bde 100644
--- a/src/DbEx.SqlServer/DbEx.SqlServer.csproj
+++ b/src/DbEx.SqlServer/DbEx.SqlServer.csproj
@@ -30,7 +30,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="CoreEx.Database.SqlServer" Version="3.8.0" />
+    <PackageReference Include="CoreEx.Database.SqlServer" Version="3.9.0" />
     <PackageReference Include="dbup-sqlserver" Version="5.0.37" />
   </ItemGroup>
 
diff --git a/src/DbEx.SqlServer/Migration/SqlServerMigration.cs b/src/DbEx.SqlServer/Migration/SqlServerMigration.cs
index f95e16a..b45ac36 100644
--- a/src/DbEx.SqlServer/Migration/SqlServerMigration.cs
+++ b/src/DbEx.SqlServer/Migration/SqlServerMigration.cs
@@ -27,7 +27,7 @@ public class SqlServerMigration : DatabaseMigrationBase
         private readonly string _databaseName;
         private readonly IDatabase _database;
         private readonly IDatabase _masterDatabase;
-        private readonly List<string> _resetBypass = new();
+        private readonly List<string> _resetBypass = [];
 
         /// <summary>
         /// Initializes an instance of the <see cref="SqlServerMigration"/> class.
@@ -50,7 +50,7 @@ public SqlServerMigration(MigrationArgsBase args) : base(args)
 
             // Defaults the schema object types unless already specified.
             if (SchemaObjectTypes.Length == 0)
-                SchemaObjectTypes = new string[] { "TYPE", "FUNCTION", "VIEW", "PROCEDURE", "PROC" };
+                SchemaObjectTypes = ["TYPE", "FUNCTION", "VIEW", "PROCEDURE", "PROC"];
 
             // Always add the dbo schema _first_ unless already specified.
             if (!Args.SchemaOrder.Contains("dbo"))
diff --git a/src/DbEx/Console/AssemblyValidator.cs b/src/DbEx/Console/AssemblyValidator.cs
index bfbf0b4..679de1f 100644
--- a/src/DbEx/Console/AssemblyValidator.cs
+++ b/src/DbEx/Console/AssemblyValidator.cs
@@ -1,5 +1,6 @@
 // Copyright (c) Avanade. Licensed under the MIT License. See https://github.com/Avanade/DbEx
 
+using CoreEx;
 using DbEx.Migration;
 using McMaster.Extensions.CommandLineUtils;
 using McMaster.Extensions.CommandLineUtils.Validation;
@@ -15,15 +16,10 @@ namespace DbEx.Console
     /// <summary>
     /// Validates the assembly name(s).
     /// </summary>
-    public class AssemblyValidator : IOptionValidator
+    /// <param name="args">The <see cref="MigrationArgs"/> to update.</param>
+    public class AssemblyValidator(MigrationArgsBase args) : IOptionValidator
     {
-        private readonly MigrationArgsBase _args;
-
-        /// <summary>
-        /// Initilizes a new instance of the <see cref="AssemblyValidator"/> class.
-        /// </summary>
-        /// <param name="args">The <see cref="MigrationArgs"/> to update.</param>
-        public AssemblyValidator(MigrationArgsBase args) => _args = args ?? throw new ArgumentNullException(nameof(args));
+        private readonly MigrationArgsBase _args = args.ThrowIfNull(nameof(args));
 
         /// <summary>
         /// Performs the validation.
@@ -45,7 +41,7 @@ public ValidationResult GetValidationResult(CommandOption option, ValidationCont
                 try
                 {
                     // Load from the specified file on the file system or by using its long form name. 
-                    list.Add(File.Exists(name) ? Assembly.LoadFrom(name!) : Assembly.Load(name!));
+                    _args.AddAssembly(File.Exists(name) ? Assembly.LoadFrom(name!) : Assembly.Load(name!));
                 }
                 catch (Exception ex)
                 {
@@ -53,7 +49,6 @@ public ValidationResult GetValidationResult(CommandOption option, ValidationCont
                 }
             }
 
-            _args.Assemblies.InsertRange(0, list.ToArray());
             return ValidationResult.Success!;
         }
     }
diff --git a/src/DbEx/Console/MigrationConsoleBase.cs b/src/DbEx/Console/MigrationConsoleBase.cs
index d4bd033..a4b5b93 100644
--- a/src/DbEx/Console/MigrationConsoleBase.cs
+++ b/src/DbEx/Console/MigrationConsoleBase.cs
@@ -153,7 +153,7 @@ public async Task<int> RunAsync(string[] args, CancellationToken cancellationTok
 
                 UpdateBooleanOption(EntryAssemblyOnlyOptionName, () =>
                 {
-                    Args.Assemblies.Clear();
+                    Args.ClearAssemblies();
                     Args.AddAssembly(Assembly.GetEntryAssembly()!);
                 });
 
@@ -416,10 +416,10 @@ public static void WriteStandardizedArgs(DatabaseMigrationBase migrator, Action<
                 migrator.Args.Logger.LogInformation("{Content}", $"  {p.Key} = {p.Value}");
             }
 
-            migrator.Args.Logger.LogInformation("{Content}", $"Assemblies{(migrator.Args.Assemblies.Count == 0 ? " = none" : ":")}");
+            migrator.Args.Logger.LogInformation("{Content}", $"Assemblies{(!migrator.Args.Assemblies.Any() ? " = none" : ":")}");
             foreach (var a in migrator.Args.Assemblies)
             {
-                migrator.Args.Logger.LogInformation("{Content}", $"  {a.FullName}");
+                migrator.Args.Logger.LogInformation("{Content}", $"  {a.Assembly.FullName}");
             }
         }
 
diff --git a/src/DbEx/DbEx.csproj b/src/DbEx/DbEx.csproj
index b8897f5..474c427 100644
--- a/src/DbEx/DbEx.csproj
+++ b/src/DbEx/DbEx.csproj
@@ -21,7 +21,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="CoreEx.Database" Version="3.8.0" />
+    <PackageReference Include="CoreEx.Database" Version="3.9.0" />
     <PackageReference Include="OnRamp" Version="2.0.0" />
   </ItemGroup>
 
diff --git a/src/DbEx/Migration/DatabaseMigrationBase.cs b/src/DbEx/Migration/DatabaseMigrationBase.cs
index 91dfb71..f9189be 100644
--- a/src/DbEx/Migration/DatabaseMigrationBase.cs
+++ b/src/DbEx/Migration/DatabaseMigrationBase.cs
@@ -25,6 +25,7 @@ public abstract class DatabaseMigrationBase : IDisposable
     {
         private const string NothingFoundText = "  ** Nothing found. **";
         private const string OnDatabaseCreateName = "post.database.create";
+        private static readonly string[] _splitters = ["\r\n", "\r", "\n"];
         private HandlebarsCodeGenerator? _dataCodeGen;
         private bool _hasInitialized = false;
 
@@ -119,11 +120,6 @@ protected DatabaseMigrationBase(MigrationArgsBase args)
         /// </summary>
         public string SchemaNamespace { get; set; } = "Schema";
 
-        /// <summary>
-        /// Gets or sets the <b>Migrations</b> scripts namespace part name.
-        /// </summary>
-        public string DataNamespace { get; set; } = "Data";
-
         /// <summary>
         /// Gets or sets the list of supported schema object types in the order of precedence.
         /// </summary>
@@ -235,7 +231,7 @@ private void PreExecutionInitialization()
             _hasInitialized = true;
 
             var list = (List<string>)Namespaces;
-            Args.ProbeAssemblies.ForEach(x => list.Add(x.GetName().Name!));
+            Args.ProbeAssemblies.ForEach(x => list.Add(x.Assembly.GetName().Name!));
 
             // Walk the assembly hierarchy.
             var alist = new List<Assembly>();
@@ -441,9 +437,9 @@ protected virtual async Task<bool> DatabaseCreateAsync(CancellationToken cancell
             var scripts = new List<DatabaseMigrationScript>();
             foreach (var ass in Args.ProbeAssemblies)
             {
-                foreach (var name in ass.GetManifestResourceNames().Where(rn => Namespaces.Any(ns => rn.StartsWith($"{ns}.{MigrationsNamespace}.", StringComparison.InvariantCulture) && rn.EndsWith($".{OnDatabaseCreateName}.sql", StringComparison.InvariantCultureIgnoreCase))).OrderBy(x => x))
+                foreach (var name in ass.Assembly.GetManifestResourceNames().Where(rn => Namespaces.Any(ns => rn.StartsWith($"{ns}.{MigrationsNamespace}.", StringComparison.InvariantCulture) && rn.EndsWith($".{OnDatabaseCreateName}.sql", StringComparison.InvariantCultureIgnoreCase))).OrderBy(x => x))
                 {
-                    scripts.Add(new DatabaseMigrationScript(ass, name) { RunAlways = true });
+                    scripts.Add(new DatabaseMigrationScript(ass.Assembly, name) { RunAlways = true });
                 }
             }
 
@@ -467,7 +463,7 @@ private async Task<bool> DatabaseMigrateAsync(CancellationToken cancellationToke
             var scripts = new List<DatabaseMigrationScript>();
             foreach (var ass in Args.ProbeAssemblies)
             {
-                foreach (var name in ass.GetManifestResourceNames().Where(rn => Namespaces.Any(ns => rn.StartsWith($"{ns}.{MigrationsNamespace}.", StringComparison.InvariantCulture))).OrderBy(x => x))
+                foreach (var name in ass.Assembly.GetManifestResourceNames().Where(rn => Namespaces.Any(ns => rn.StartsWith($"{ns}.{MigrationsNamespace}.", StringComparison.InvariantCulture))).OrderBy(x => x))
                 {
                     // Ignore any/all database create scripts.
                     if (name.EndsWith($".{OnDatabaseCreateName}.sql", StringComparison.InvariantCultureIgnoreCase))
@@ -477,7 +473,7 @@ private async Task<bool> DatabaseMigrateAsync(CancellationToken cancellationToke
                     var order = name.EndsWith(".pre.deploy.sql", StringComparison.InvariantCultureIgnoreCase) ? 1 :
                                 name.EndsWith(".post.deploy.sql", StringComparison.InvariantCultureIgnoreCase) ? 3 : 2;
 
-                    scripts.Add(new DatabaseMigrationScript(ass, name) { GroupOrder = order, RunAlways = order != 2 });
+                    scripts.Add(new DatabaseMigrationScript(ass.Assembly, name) { GroupOrder = order, RunAlways = order != 2 });
                 }
             }
 
@@ -534,7 +530,7 @@ private async Task<bool> DatabaseSchemaAsync(CancellationToken cancellationToken
             Logger.LogInformation("{Content}", $"  Probing for embedded resources: {string.Join(", ", GetNamespacesWithSuffix($"{SchemaNamespace}.*.sql"))}");
             foreach (var ass in Args.ProbeAssemblies)
             {
-                foreach (var rn in ass.GetManifestResourceNames().OrderBy(x => x))
+                foreach (var rn in ass.Assembly.GetManifestResourceNames().OrderBy(x => x))
                 {
                     // Filter on schema namespace prefix and suffix of '.sql'.
                     if (!(Namespaces.Any(x => rn.StartsWith($"{x}.{SchemaNamespace}.", StringComparison.InvariantCulture) && rn.EndsWith(".sql", StringComparison.InvariantCultureIgnoreCase))))
@@ -544,7 +540,7 @@ private async Task<bool> DatabaseSchemaAsync(CancellationToken cancellationToken
                     if (scripts.Any(x => x.Name == rn))
                         continue;
 
-                    scripts.Add(new DatabaseMigrationScript(ass, rn));
+                    scripts.Add(new DatabaseMigrationScript(ass.Assembly, rn));
                 }
             }
 
@@ -695,20 +691,32 @@ protected virtual async Task<bool> DatabaseResetAsync(CancellationToken cancella
         /// </summary>
         private async Task<bool> DatabaseDataAsync(CancellationToken cancellationToken)
         {
-            Logger.LogInformation("{Content}", $"  Probing for embedded resources: {string.Join(", ", GetNamespacesWithSuffix($"{DataNamespace}.*", true))}");
+            var names = new List<string>();
+            foreach (var ass in Args.Assemblies)
+            {
+                foreach (var dns in ass.DataNamespaces)
+                {
+                    names.Add($"{ass.Assembly.GetName().Name}.{dns}.*");
+                }
+            }
+
+            Logger.LogInformation("{Content}", $"  Probing for embedded resources: {string.Join(", ", names)}");
 
             var list = new List<(Assembly Assembly, string ResourceName)>();
-            foreach (var ass in Args.Assemblies.Distinct()) // Assumed data builds on top of earlier (do not use ProbeAssemblies as this is reversed).
+            foreach (var ass in Args.Assemblies)
             {
-                foreach (var rn in ass.GetManifestResourceNames().OrderBy(x => x))
+                foreach (var rn in ass.Assembly.GetManifestResourceNames().OrderBy(x => x))
                 {
-                    // Filter on schema namespace prefix and supported suffixes.
-                    if (!Namespaces.Any(x => rn.StartsWith($"{x}.{DataNamespace}.", StringComparison.InvariantCulture) && (rn.EndsWith(".sql", StringComparison.InvariantCultureIgnoreCase) 
-                        || rn.EndsWith(".yaml", StringComparison.InvariantCultureIgnoreCase) || rn.EndsWith(".yml", StringComparison.InvariantCultureIgnoreCase)
-                        || rn.EndsWith(".json", StringComparison.InvariantCultureIgnoreCase) || rn.EndsWith(".jsn", StringComparison.InvariantCultureIgnoreCase))))
-                        continue;
+                    foreach (var dns in ass.DataNamespaces)
+                    {
+                        // Filter on schema namespace prefix and supported suffixes.
+                        if (!Namespaces.Any(x => rn.StartsWith($"{x}.{dns}.", StringComparison.InvariantCulture) && (rn.EndsWith(".sql", StringComparison.InvariantCultureIgnoreCase)
+                            || rn.EndsWith(".yaml", StringComparison.InvariantCultureIgnoreCase) || rn.EndsWith(".yml", StringComparison.InvariantCultureIgnoreCase)
+                            || rn.EndsWith(".json", StringComparison.InvariantCultureIgnoreCase) || rn.EndsWith(".jsn", StringComparison.InvariantCultureIgnoreCase))))
+                            continue;
 
-                    list.Add((ass, rn));
+                        list.Add((ass.Assembly, rn));
+                    }
                 }
             }
 
@@ -818,7 +826,7 @@ protected virtual async Task<bool> DatabaseDataAsync(List<DataTable> dataTables,
         /// <summary>
         /// Gets the <see cref="Namespaces"/> with the specified namespace suffix applied.
         /// </summary>
-        private IEnumerable<string> GetNamespacesWithSuffix(string suffix, bool reverse = false)
+        private string[] GetNamespacesWithSuffix(string suffix, bool reverse = false)
         {
             if (suffix == null)
                 throw new ArgumentNullException(nameof(suffix));
@@ -829,7 +837,7 @@ private IEnumerable<string> GetNamespacesWithSuffix(string suffix, bool reverse
                 list.Add($"{ns}.{suffix}");
             }
 
-            return list.Count == 0 ? new string[] { "(none)" } : [.. list];
+            return list.Count == 0 ? ["(none)"] : [.. list];
         }
 
         /// <summary>
@@ -850,6 +858,7 @@ public async Task<bool> CreateScriptAsync(string? name = null, IDictionary<strin
         /// </summary>
         private async Task<bool> CreateScriptInternalAsync(string? name, IDictionary<string, string?>? parameters, CancellationToken cancellationToken)
         {
+
             name ??= "Default";
             var rn = $"Script{name}_sql";
 
@@ -867,7 +876,7 @@ private async Task<bool> CreateScriptInternalAsync(string? name, IDictionary<str
 
             // Extract the filename from content if specified.
             var data = new { Parameters = parameters ?? new Dictionary<string, string?>() };
-            var lines = txt.Split(new string[] { "\r\n", "\r", "\n" }, StringSplitOptions.None);
+            var lines = txt.Split(_splitters, StringSplitOptions.None);
             string fn = "new-script";
             foreach (var line in lines)
             {
diff --git a/src/DbEx/Migration/MigrationArgsBase.cs b/src/DbEx/Migration/MigrationArgsBase.cs
index 9bc7f0c..b8d9fd3 100644
--- a/src/DbEx/Migration/MigrationArgsBase.cs
+++ b/src/DbEx/Migration/MigrationArgsBase.cs
@@ -15,6 +15,8 @@ namespace DbEx.Migration
     /// </summary>
     public abstract class MigrationArgsBase : OnRamp.CodeGeneratorDbArgsBase
     {
+        private readonly List<MigrationAssemblyArgs> _assemblies = [new MigrationAssemblyArgs(typeof(MigrationArgs).Assembly)];
+
         /// <summary>
         /// Gets the <see cref="DatabaseMigrationBase.DatabaseName"/> <see cref="Parameters"/> name.
         /// </summary>
@@ -43,12 +45,12 @@ public abstract class MigrationArgsBase : OnRamp.CodeGeneratorDbArgsBase
         /// <summary>
         /// Gets the <see cref="Assembly"/> list to use to probe for assembly resource (in defined sequence); will automatically add this (DbEx) assembly also (therefore no need to explicitly specify).
         /// </summary>
-        public List<Assembly> Assemblies { get; } = [typeof(MigrationArgs).Assembly];
+        public IEnumerable<MigrationAssemblyArgs> Assemblies => _assemblies;
 
         /// <summary>
         /// Gets the <see cref="Assemblies"/> reversed in order for probe-based sequencing.
         /// </summary>
-        public IEnumerable<Assembly> ProbeAssemblies => Assemblies.Distinct().Reverse();
+        public IEnumerable<MigrationAssemblyArgs> ProbeAssemblies => Assemblies.Reverse();
 
         /// <summary>
         /// Gets the runtime parameters.
@@ -93,17 +95,29 @@ public abstract class MigrationArgsBase : OnRamp.CodeGeneratorDbArgsBase
         /// <remarks>This is additional to any pre-configured database provider specified <see cref="DatabaseMigrationBase.DataResetFilterPredicate"/>.</remarks>
         public Func<DbSchema.DbTableSchema, bool>? DataResetFilterPredicate { get; set; }
 
+        /// <summary>
+        /// Clears the <see cref="Assemblies"/> by removing all existing items.
+        /// </summary>
+        public void ClearAssemblies() => _assemblies.Clear();
+
         /// <summary>
         /// Adds one or more <paramref name="assemblies"/> to the <see cref="Assemblies"/>.
         /// </summary>
         /// <param name="assemblies">The assemblies to add.</param>
         /// <remarks>Where a specified <see cref="Assembly"/> item already exists within the <see cref="Assemblies"/> it will not be added again.</remarks>
-        public void AddAssembly(params Assembly[] assemblies)
+        public void AddAssembly(params Assembly[] assemblies) => AddAssembly(assemblies.Select(x => new MigrationAssemblyArgs(x)).ToArray());
+
+        /// <summary>
+        /// Adds one or more <paramref name="assemblies"/> to the <see cref="Assemblies"/>.
+        /// </summary>
+        /// <param name="assemblies">The assemblies to add.</param>
+        /// <remarks>Where a specified <see cref="Assembly"/> item already exists within the <see cref="Assemblies"/> it will not be added again.</remarks>
+        public void AddAssembly(params MigrationAssemblyArgs[] assemblies)
         {
             foreach (var assembly in assemblies)
             {
-                if (!Assemblies.Contains(assembly))
-                    Assemblies.Add(assembly);
+                if (!_assemblies.Any(x => x.Assembly == assembly.Assembly))
+                    _assemblies.Add(assembly);
             }
         }
 
@@ -113,28 +127,36 @@ public void AddAssembly(params Assembly[] assemblies)
         /// <param name="assemblyToFind">The <see cref="Assembly"/> to find within the existing <see cref="Assemblies"/>.</param>
         /// <param name="assemblies">The assemblies to add</param>
         /// <remarks>Where a specified <see cref="Assembly"/> item already exists within the <see cref="Assemblies"/> it will not be added again.</remarks>
-        public void AddAssemblyAfter(Assembly assemblyToFind, params Assembly[] assemblies)
+        public void AddAssemblyAfter(Assembly assemblyToFind, params Assembly[] assemblies) => AddAssemblyAfter(assemblyToFind, assemblies.Select(x => new MigrationAssemblyArgs(x)).ToArray());
+
+        /// <summary>
+        /// Adds one or more <paramref name="assemblies"/> to the <see cref="Assemblies"/> after the specified <paramref name="assemblyToFind"/>; where not found, will be added to the end.
+        /// </summary>
+        /// <param name="assemblyToFind">The <see cref="Assembly"/> to find within the existing <see cref="Assemblies"/>.</param>
+        /// <param name="assemblies">The assemblies to add</param>
+        /// <remarks>Where a specified <see cref="Assembly"/> item already exists within the <see cref="Assemblies"/> it will not be added again.</remarks>
+        public void AddAssemblyAfter(Assembly assemblyToFind, params MigrationAssemblyArgs[] assemblies)
         {
-            var index = Assemblies.IndexOf(assemblyToFind ?? throw new ArgumentNullException(nameof(assemblyToFind)));
+            var index = _assemblies.FindIndex(x => x.Assembly == (assemblyToFind ?? throw new ArgumentNullException(nameof(assemblyToFind))));
             if (index < 0)
             {
                 AddAssembly(assemblies);
                 return;
             }
 
-            var newAssemblies = new List<Assembly>();
+            var newAssemblies = new List<MigrationAssemblyArgs>();
             foreach (var assembly in assemblies)
             {
-                if (!Assemblies.Contains(assembly))
+                if (!_assemblies.Any(x => x.Assembly == assembly.Assembly) && !newAssemblies.Any(x => x.Assembly == assembly.Assembly))
                     newAssemblies.Add(assembly);
             }
 
 
-            Assemblies.InsertRange(index + 1, newAssemblies);
+            _assemblies.InsertRange(index + 1, newAssemblies);
         }
 
         /// <summary>
-        /// Adds a parameter to the <see cref="MigrationArgsBase.Parameters"/> where it does not already exist; unless <paramref name="overrideExisting"/> is selected then it will add or override.
+        /// Adds a parameter to the <see cref="Parameters"/> where it does not already exist; unless <paramref name="overrideExisting"/> is selected then it will add or override.
         /// </summary>
         /// <param name="key">The parameter key.</param>
         /// <param name="value">The parameter value.</param>
@@ -155,8 +177,8 @@ protected void CopyFrom(MigrationArgsBase args)
             base.CopyFrom(args ?? throw new ArgumentNullException(nameof(args)));
 
             MigrationCommand = args.MigrationCommand;
-            Assemblies.Clear();
-            Assemblies.AddRange(args.Assemblies);
+            _assemblies.Clear();
+            _assemblies.AddRange(args.Assemblies);
             Parameters.Clear();
             args.Parameters.ForEach(x => Parameters.Add(x.Key, x.Value));
             Logger = args.Logger;
diff --git a/src/DbEx/Migration/MigrationArgsBaseT.cs b/src/DbEx/Migration/MigrationArgsBaseT.cs
index 9f707b2..f85dfcf 100644
--- a/src/DbEx/Migration/MigrationArgsBaseT.cs
+++ b/src/DbEx/Migration/MigrationArgsBaseT.cs
@@ -23,6 +23,17 @@ public new TSelf AddAssembly(params Assembly[] assemblies)
             return (TSelf)this;
         }
 
+        /// <summary>
+        /// Adds one or more <paramref name="assemblies"/> to the <see cref="MigrationArgsBase.Assemblies"/>.
+        /// </summary>
+        /// <param name="assemblies">The assemblies to add.</param>
+        /// <returns>The current <see cref="MigrationArgsBase{TSelf}"/> instance to support fluent-style method-chaining.</returns>
+        public new TSelf AddAssembly(params MigrationAssemblyArgs[] assemblies)
+        {
+            base.AddAssembly(assemblies);
+            return (TSelf)this;
+        }
+
         /// <summary>
         /// Adds one or more <paramref name="types"/> (being the underlying <see cref="Type.Assembly"/>) to <see cref="MigrationArgsBase.Assemblies"/>.
         /// </summary>
@@ -43,17 +54,8 @@ public TSelf AddAssembly(params Type[] types)
         /// <summary>
         /// Adds the <typeparamref name="TAssembly"/> (being the underlying <see cref="Type.Assembly"/>) to <see cref="MigrationArgsBase.Assemblies"/>.
         /// </summary>
-        public TSelf AddAssembly<TAssembly>() => AddAssembly(typeof(TAssembly));
-
-        /// <summary>
-        /// Adds the <typeparamref name="TAssembly1"/> and <typeparamref name="TAssembly2"/> (being the underlying <see cref="Type.Assembly"/>) to <see cref="MigrationArgsBase.Assemblies"/>.
-        /// </summary>
-        public TSelf AddAssembly<TAssembly1, TAssembly2>() => AddAssembly(typeof(TAssembly1), typeof(TAssembly2));
-
-        /// <summary>
-        /// Adds the <typeparamref name="TAssembly1"/>, <typeparamref name="TAssembly2"/> and <typeparamref name="TAssembly3"/> (being the underlying <see cref="Type.Assembly"/>) to <see cref="MigrationArgsBase.Assemblies"/>.
-        /// </summary>
-        public TSelf AddAssembly<TAssembly1, TAssembly2, TAssembly3>() => AddAssembly(typeof(TAssembly1), typeof(TAssembly2), typeof(TAssembly3));
+        /// <param name="dataNamespaces">The <see cref="MigrationAssemblyArgs.DataNamespaces"/>; defaults to <see cref="MigrationAssemblyArgs.DefaultDataNamespace"/>.</param>
+        public TSelf AddAssembly<TAssembly>(params string[] dataNamespaces) => AddAssembly(new MigrationAssemblyArgs(typeof(TAssembly).Assembly, dataNamespaces));
 
         /// <summary>
         /// Adds a parameter to the <see cref="MigrationArgsBase.Parameters"/> where it does not already exist; unless <paramref name="overrideExisting"/> is selected then it will add or override.
diff --git a/src/DbEx/Migration/MigrationAssemblyArgs.cs b/src/DbEx/Migration/MigrationAssemblyArgs.cs
new file mode 100644
index 0000000..7a15f61
--- /dev/null
+++ b/src/DbEx/Migration/MigrationAssemblyArgs.cs
@@ -0,0 +1,39 @@
+// Copyright (c) Avanade. Licensed under the MIT License. See https://github.com/Avanade/DbEx
+
+using CoreEx;
+using System.Reflection;
+
+namespace DbEx.Migration
+{
+    /// <summary>
+    /// Provides <see cref="Assembly"/> arguments.
+    /// </summary>
+    public class MigrationAssemblyArgs
+    {
+        /// <summary>
+        /// Gets or sets the default <b>Data</b> namespace part name.
+        /// </summary>
+        public static string DefaultDataNamespace { get; set; } = "Data";
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MigrationAssemblyArgs"/>.
+        /// </summary>
+        /// <param name="assembly">The <see cref="System.Reflection.Assembly"/>.</param>
+        /// <param name="dataNamespaces">The <see cref="DataNamespaces"/>; defaults to <see cref="DefaultDataNamespace"/>.</param>
+        public MigrationAssemblyArgs(Assembly assembly, params string[] dataNamespaces)
+        {
+            Assembly = assembly.ThrowIfNull(nameof(Assembly));
+            DataNamespaces = dataNamespaces is null || dataNamespaces.Length == 0 ? [DefaultDataNamespace] : dataNamespaces;
+        }
+
+        /// <summary>
+        /// Gets the <see cref="System.Reflection.Assembly"/>.
+        /// </summary>
+        public Assembly Assembly { get; }
+
+        /// <summary>
+        /// Gets the <b>Data</b> namespace part name(s).
+        /// </summary>
+        public string[] DataNamespaces { get; }
+    }
+}
\ No newline at end of file
diff --git a/tests/DbEx.Test.Console/Program.cs b/tests/DbEx.Test.Console/Program.cs
index 78d617a..ba441f8 100644
--- a/tests/DbEx.Test.Console/Program.cs
+++ b/tests/DbEx.Test.Console/Program.cs
@@ -9,7 +9,7 @@ public class Program
             .Create<Program>("Data Source=.;Initial Catalog=DbEx.Console;Integrated Security=True;TrustServerCertificate=true")
             .Configure(c =>
             {
-                c.Args.AddAssembly(typeof(DbEx.Test.OutboxConsole.Program).Assembly);
+                c.Args.AddAssembly<DbEx.Test.OutboxConsole.Program>("Data", "Data2");
                 c.Args.AddSchemaOrder("Test", "Outbox");
                 c.Args.DataParserArgs.Parameter("DefaultName", "Bazza")
                                      .RefDataColumnDefault("SortOrder", i => i)